题解 | #牛客的课程订单分析(七)#

第二列显示这个客户端(或者是拼团订单)有多少订单——分组计数！

select 
(case when is_group_buy = 'Yes' then 'GroupBuy' else b.name end) as source, count(*) cnt
from 
(select *, count(*) over(partition by user_id) as n from order_info
where date > '2025-10-15'
and product_name in ('C++','Java','Python')
and status = 'completed') a left join client b on a.client_id = b.id
where n > 1
group by source
order by source asc;